Electromechanical actuators are used for a wide variety of purposes. Actuation of an electromechanical actuator typically involves a displacement of the electromechanical actuator from a rest position to an actuated or activated position. Generally, the actuation of an electromechanical actuator triggers a consequent or resultant effect. For instance, an actuation of a computer mouse button can trigger the generation of a signal for selecting an icon on a computer screen. In addition, an actuation of a keypad carried by a keyboard can result in the generation and display of an alphanumeric character on a computer screen.
Conventionally, it has not been possible to control the actuation of electromechanical actuators (e.g., computer mouse buttons and keypads). More often than not, a user is unable to control, for example select or adjust, a force that is required for actuating an electromechanical actuator.
However, it has recently been recognized that it can be advantageous or desirable to control the actuation of electromechanical actuators, for instance control the quantity of force required for actuating electromechanical actuators. Accordingly, there have been attempts at enabling or effectuating such control of actuation of electromechanical actuators (e.g., mouse buttons and keypads carried by a keyboard).
U.S. Pat. No. 5,466,901 of Isao Mochizuki discloses an adjustable touch computer keyboard that has scissor-like leg structures for supporting keytops or keypads with compression coil springs used to assist in biasing the keytops or keypads to an “up” position. U.S. Pat. No. 5,466,901 also discloses the use of a slide mechanism for adjusting the compression of the compression coil springs to vary the “touch” or “feel” of the keys.
In addition, U.S. Pat. No. 4,500,758 of Peter U. Guckenheimer is directed to a keyboard having a mechanical cam means to adjust the length of the keystroke to vary the “tactile feel” of the keys. The U.S. Pat. No. 5,220,318 of Darrell S. Staley describes an adjustable “touch” control using magnetic key plungers located within adjustable magnetic fields to vary the forces required to depress the keys and activate the keyswitches.
Furthermore, U.S. Pat. No. 4,795,888 of Andrew R. MacFarlane discloses a computer keyboard with a variable force keystroke feature that includes an apertured air pressure bladder positioned underneath the keytops. The air pressure in the bladder can be adjusted to vary the keystroke force required to actuate the keyswitch. However, a potential disadvantage to the design of U.S. Pat. No. 4,795,888 is that the spring action of the air pressure is not linear over the full stroke of the key but rather is more exponential in character, thereby affecting the overall “tactile feel” of the keys. In addition, with the variable force keystroke feature of U.S. Pat. No. 4,795,888, the force required to depress or actuate a particular keytop is dependent upon the size of that keytop.
Generally, existing designs and techniques for controlling, for instance selecting and adjusting, the force that is required for actuating keypads or keyswitches are relatively complex and/or costly. Many existing designs and techniques for controlling the “tactile feel” of keypads or keyswitches have been unreliable and/or relatively expensive. There is therefore a need to be able to control a force required for actuating an electromechanical actuator such as a keypad or keyswitch in a less costly, simpler, and/or more convenient manner.